1. A measurement of the electrical potentials generated in the inner ear as a result of sound stimulation.
2. The measurement of electrical activity produced when the cochlea is stimulated.

A needle electrode is passed through the eardrum and placed on the cochlea, the part of the inner ear concerned with hearing. The electrical activity is then recorded.

3. A diagnostic test in which a probe is inserted into the cochlea in the inner ear to measure and to record electrical activity.

Certain kinds of distortions may indicate the presence of disease.